The present invention relates generally to a retail checkout terminal, and especially to self-service terminals. More particularly, the invention concerns systems and methods for improving the security of self-service checkout processes and to personalize the security features based on customer metrics.
In the retail grocery or supermarket industry, the impetus to reduce labor costs has focused on reducing or eliminating the amount of time required to handle and/or process the products purchased by the customer. To this end, a number of self-service checkout terminals have been developed which substantially eliminate the need for a checkout clerk. In particular, the typical self-service checkout terminal is operated by the customer without the aid of a checkout clerk. In such a system, the customer scans individual items for purchase across a scanner and then places the scanned items into a grocery bag. The customer then pays for the purchases either at the self-service terminal itself or at a central payment area staffed by a store cashier.
The customer typically has little or no training in the operation of a self-service checkout terminal prior to his/her initial use of the terminal. Customer inexperience and sometimes more nefarious intentions in the use of the self-service checkout require the integration of some form of security into the checkout terminal. Such security prevents a customer from either inadvertently or deliberately placing an item into a grocery bag without first scanning the item to enter the price of the item onto the final bill.
Thus, the typical self-service terminal includes security systems that monitor the operation of the terminal and the activities of the customer. For example, weight scales are incorporated into the terminal to monitor the total weight of the items brought by the customer to the terminal and the total weight of the items placed in a grocery bag. In such security systems, a software routine is executed by a computer or processor associated with the terminal that analyzes the signal output from the weight scale, as well as other user-interfaces of the terminal. The typical software routine compares the weight of each item as it is scanned with a database of expected weight values. Any discrepancy results in the generation of an error message and a pause in the checkout routine until the customer takes appropriate corrective action, such as re-scanning the merchandise.
One known self-checkout terminal 10 used in a supermarket setting is depicted in FIG. 1. The terminal 10 includes a product weight scale 12 used to sell items by weight and a scanner 14 associated with the scale. A bagging scale 20 is provided adjacent the scanner to support grocery bags 40 into which the customer places each newly scanned item. The terminal 10 includes a cart scale sized to support a fully loaded shopping cart 21 and a basket scale 19 configured to support a shopping basket 23 full of products. Each of the scales 12, 18, 19 and 20 include at least one weight detector, such as a pressure sensor or a load cell sensor, which is operable to generate a signal in response to the weight of the item(s) placed on the scale. A kiosk 24 includes a display 32, data input device 34 and a payment device 30. A computer or processor 26 is resident within the terminal and executes various software routines associated with the self-checkout process.
One of those routines accepts weight signals from the scales 18, 19 and 20. In one type of weight verification routine, the mean weight Mn of each product or item 1 through n available in the supermarket is stored in a database along with a weight standard deviation SDn for each item. As an item is scanned by the scanner 14 and placed on a scale 18, 19 or 20, the weight measured at the scale 18,19 or 20 is compared to a weight range calculated from the mean and standard deviation data extracted from the database for that item. If the weight falls within a calculated range Mn± the standard deviation SDn (optionally multiplied by an arbitrary constant A), the entry is accepted. If the weight falls outside this range the entry is rejected and the customer is instructed to re-scan and/or re-weigh the item. In addition, in some terminals, a weight error is communicated to a store attendant as part of the terminal security measures. The routine continuously updates the mean weight and standard deviation values for each item with each new accepted observation of the weight of that item.
Since the scales form a critical link in the self-checkout process, the uncompromised operation of the scales is critical. Unfortunately, the weight scale is a common point of error or failure for the checkout terminal due to the high likelihood of spillage or the collection of debris in the working elements of the scales that ultimately interferes with the normal scale operation. For example, a very common failure occurs when a foreign object becomes lodged between the top plate of the scale and the adjacent cabinetry. When the object prevents movement of the scale, the failure is easily detected but the scale is rendered unusable. However, in the worst case, the foreign object simply increases the drag on the scale movement, typically producing a low weight error. When this type of failures occurs, the ability to verify the weight of a purchased item is compromised, subjecting the customer and store attendant to increased numbers of security messages and interventions. This intervention is especially troubling to the honest and experienced customer who is attempting to use the self-checkout terminal properly.
These failure modes are difficult to detect, often requiring complete failure before the detrimental condition is recognized. In a typical case, the weight scale behavior deteriorates over time, gradually impacting the system to ever-increasing degrees until a complete failure threshold has been reached. One approach to finding a potential scale failure is to run a calibration test on the product weight scale at each self-checkout terminal in the store. Of course, this approach is very cumbersome, time consuming and manpower intensive.
Thus, there is a need for a system and method that can automatically test a self-service checkout product weight scale continuously throughout the day while allowing the terminal to remain in service and without requiring human intervention or involvement in the test. The system and method should be capable of operating generally transparently to the customer, meaning that there is no appreciable effect on the amount of time necessary for a customer to complete a sales transaction at the terminal.